BEEN_Nath_58 wrote on 2022-12-28, 13:33:

...
[*]This also adds a question for the desktop movie app, if it really needs overlay, is it definitely because of the support for DDSCAPS_OVERLAY or something else?[/list]

Desktop movie has an indirect dependency on real HW overlays. Namely it relies on "Overlay Mixer" Directshow renderer to achieve seamless desktop background movie playing with minimal system resource usage.
If no HW overlay is found then Desktop movie cannot create a fully working Directshow graph since Overlay Mixer refuses connections to its pins.
https://learn.microsoft.com/en-us/windows/win … ay-mixer-filter

The Overlay Mixer uses DirectDraw for rendering. It requires an overlay surface on the graphics card...
To test whether the graphics driver supports hardware overlay, call IDirectDraw7::GetCaps. If the dwMaxVisibleOverlays field in the DDCAPS structure is greater than zero, the driver supports hardware overlay.

Falcosoft wrote on 2022-12-29, 09:02:

Desktop movie has an indirect dependency on real HW overlays. Namely it relies on "Overlay Mixer" Directshow renderer to achieve […]
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BEEN_Nath_58 wrote on 2022-12-28, 13:33:

...
[*]This also adds a question for the desktop movie app, if it really needs overlay, is it definitely because of the support for DDSCAPS_OVERLAY or something else?[/list]

Desktop movie has an indirect dependency on real HW overlays. Namely it relies on "Overlay Mixer" Directshow renderer to achieve seamless desktop background movie playing with minimal system resource usage.
If no HW overlay is found then Desktop movie cannot create a fully working Directshow graph since Overlay Mixer refuses connections to its pins.
https://learn.microsoft.com/en-us/windows/win … ay-mixer-filter

The Overlay Mixer uses DirectDraw for rendering. It requires an overlay surface on the graphics card...
To test whether the graphics driver supports hardware overlay, call IDirectDraw7::GetCaps. If the dwMaxVisibleOverlays field in the DDCAPS structure is greater than zero, the driver supports hardware overlay.

DxWnd creates caps to ensure the dwMaxVisibleOverlays value is 0x1 and DDSCAPS_OVERLAY is YES (I tested attaching dxview.exe to it). It then throws the overlay surface at the primary surface. So it must be some hooking problem, or DirectShow that it doesn't handle well. Anyways I appreciate the effort and the answers, the entire overlay development will take a while, and if dgVoodoo2 adds it too, it shall not be that soon.

Hardware overlay was used generally by video capture programs, picture viewers, video players, DVD players ,,also some games used it like the godfather etc
on the Commodore Amiga this overlay feature was called PIP ( picture in picture)

what basically does is realtime scale/resize of the image or video captured
this feature was used by the old TV capture cards for a better TV quality of image, fast rezising scaling etc also used by the drivers of old webcams

Hardware overlay worked until winvista, but winvista disabled aero when a program which uses overlay launchs because overlay was incompatible with the Aero transparences etc yet in windows vista Hardware overlay programs cause crashes and problems etc

So on win 7 and later this feature was disabled by Microsoft so basically if you want to use a program which uses overlay the best way to go is WinXP + GFX card which support 100% winxp : ex a geforce 950

and Im almost sure the last geforce seriess which support hardware overlay are the 900 series (maxwell)

BTT, I was trying to make to work hardware overlay on win 10 here using such registry keys cited her in this thread but nothing worked here, the overlay demo don't work here, also the program Dscaler 4.15 which uses overlay to capture video does not work neither

anyways some of the info here in this thread is incorrect so I will try to investigate a bit to find a clear way to make hardware overlay works in win 10 and win 11
see ya soon

Not related to dgVoodoo2rectly, but it seems like modern AMD cards have overlay support? GetCaps returns-

OVERLAYARITHSTRETCHY+OVERLAYSHRINKX+OVERLAYSHRINKY+OVERLAYSTRETCHX+OVERLAYSTRETCHY+OVERLAYDEINTERLACE+OVERLAYFILTER+OVERLAYARITHSTRETCHY

which isn't present on my Nvidia GF10 card